BE was a huge mistake. Arabic numerals originated in a right-to-left language too.

depending on what size integer it is

That's the worst part about BE: values that have a size-dependent term in them, in addition to a subtraction. 2^n vs. 2^(l-n) and 256^N vs 256^(L-N).

According to Linus, BE has been "effectively dead" for at least a decade: https://news.ycombinator.com/item?id=9451284

Arabic numerals originated in India, were languages are written left to right.